The idea of using the relay is to pull power from the battery rather than the harness - I have my relay back near the pump with a 12 ga wire from the battery going to it. I also have an oil pressure safety switch installed in the block where the oil pressure sender would be that will kill the pump if the oil pressure drops to zero, but will bypass the switch when starting the motor - the schematic is on the forum for that. I have run Geronimo like that for almost 30 years with that setup - the safety switch lasted over 20 years before it finally went, shooting oil out the terminals. Put in a new one, and away I went.